Pig Blood Research Articles

Antioxidant Properties and Transepithelial Transportation of Di-/tripeptides Derived from Simulated Gastrointestinal Digestion of Pig Blood Cells Hydrolysates

Pig blood is an important by-product of the meat industry, which has not been fully utilized. In this study, Pig Blood Cells (PBC) were hydrolyzed by Alcalase and followed with simulated Gastrointestinal (GI) digestion to generate bioactive peptides. The antioxidant properties and the intestinal epithelial cells permeabilities of di-/tripeptides from PBC Hydrolysates (PBCH) were investigated. PBCH showed higher 1,1-diphenyl-2-picrylhydrazy and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activities than PBC, although the activities were weakened by GI digestion. Besides, both PBCH and GI digested PBCH (PBCH-GI) significantly improved cell viability and suppressed the production of reactive oxygen species under oxidative stress conditions in Caco-2 cells. By using ultra performance liquid chromatography–orbitraptandem–mass spectrometry (UPLC–Orbitrap–MS/MS) technique, 5, 144, and 150 di-/tripeptides sequences were characterized in the PBC, PBCH and PBCH-GI groups, respectively. The transepithelial transportation revealed that the permeability of di-/tripeptides through intestinal epithelial cells varied from 0.48% to 10.80%, and the peptides SDL, GDL, KF, FE exhibit high permeability values of 10.80%, 10.62%, 8.79% and 7.54%, respectively. These results indicate that PBCH has strong antioxidant properties and contains absorbable di-/tripeptides, which is promising for functional food additive.

Biomedical cell product model for preclinical studies carried out on a large laboratory animal

Objective : to develop a model of a biomedical cell product that is consistent with the «homologous drug» strategy based on protocols for preparing the cell component and scaffold carrier for preclinical studies on a large laboratory animal (pig). Materials and methods . Biomedical cell products and skin equivalents (SE), were formed using plasma cryoprecipitate prepared from blood plasma of healthy donors and mesenchymal stem cells (MSCs) of human adipose tissue. Cryoprecipitate from pig blood plasma and human adipose tissue-derived MSCs were used to form model skin equivalents (mSE). Bright-field microscopy, phase-contrast microscopy (Leica DMI 3000B) and fluorescence microscopy (Cytation 5 imager; BioTek, USA) were used to monitor the state of cells in the culture and in the composition of the equivalents. Scaffolds for equivalents were tested for cytotoxicity (MTT test, direct contact method). The cell distribution density was characterized by author’s method (Patent No. 2675376 of the Russian Federation). Results . An mSE was developed for preclinical studies on a large laboratory animal (pig). In the mSE, components that change from halogen to xenogenic conditions during transplantation to the animal were replaced. A comprehensive approach to preparing mSE was presented. It includes sampling of primary pig biomaterial, extraction and characterization of adipose tissue-derived MSCs, preparation of a scaffold carrier for the corresponding «homologous drug» strategy. Cytotoxicity of the mSE scaffold was evaluated. It was shown that mSE provides mechanical support (similar to SE) to cells, as well as comparable development of cellular events during cultivation. Conclusion . A model of a biomedical cell product was developed. This model is consistent with the «homologous drug» strategy for preclinical studies on a large laboratory animal (pig). The paper presented a comprehensive approach to developing a model equivalent based on protocols for preparation and testing of the cellular component, the scaffold carrier and the ready-to-use model equivalent.

Practical aspects on identification, cultivation and characteristics of varicella-zoster virus isolates

Until now, it has been considered that infectivity of the varicella-zoster virus (VZV) is closely related to target cell, and newly formed virus is not released into the culture medium. It is also known that it is hard to grow VZV in cell cultures, due to its slow replication rate and a limited range of sensitive cell cultures. In addition, VZV isolation depends on type of cell culture used, nature of clinical material, presence of viable virus and transport time. Objectives. To study production of infectious extracellular VZV in various cell cultures. Materials and methods. Eight cell cultures were used, including human embryonic diploid lung cells and human embryonic dermomuscular tissue (KM-27), as well as continuous human and monkey cell lines. Crusts detached from vesicular lesions were used as clinical isolates, which were placed into cryo-vials added with transport medium and transferred in liquid nitrogen. VZV infectivity was assessed in cell cultures by using hemo-adsorption assay with erythrocyte suspension isolated from guinea pig or human zero group blood and confirmed by indirect immunofluorescence with polyclonal sera from varicella or herpes zoster convalescents. Results. There were examined 27 clinical samples consisting of crusts from vesicular lesions isolated from patients with chickenpox, as well as one sample from 63-year old patient with exacerbated recurrent herpes zoster. Primary infection with clinical isolates was performed on diploid human lung embryo cells (HLEC) at low temperature. It was found that clinical samples collected within day 1–18 inclusive after the onset of skin eruption were able to induce cytopathic effects in HLEC cell monolayer such as cytolysis around dermal crusts. Specificity of cytopathic effect was confirmed by using real-time polymerase chain reaction (RT-PCR). Viral antigens were prepared on 7 cell lines infected with the laboratory strain Ellen VZV (USA) to assess the immune sera. A high anti-VZV specificity of mouse sera was detected by ELISA while all the lysates of infected cell lines were used as the solid-phase sorbent. In experiments on VZV reproduction demonstrated that extracellular virus was released into the culture medium starting from day 1 after infection of target cells, and infectivity of the virus-containing fluid ascends during further cultivation.

Phagocytic Activity of Neutrophils in the Blood of Pigs that Received A “Microecological System” Alternative to Antibiotics

Phagocytic Activity of Neutrophils in the Blood of Pigs that Received A “Microecological System” Alternative to Antibiotics

Storability of porcine blood in forensics: How far should we go?

Previous studies on the storability of porcine blood for bloodstain pattern analysis (BPA) focused on abattoir blood only and did not include measurements of viscoelasticity. Although known to provoke echinocyte formation, EDTA is widely used for BPA issues. We compared ageing samples taken from live pigs with abattoir blood and detected considerable differences in hematocrit (HCT), total protein and shear viscosity that even worsened with time. Upon storage, high shear viscosity continuously increased, resulting in a partial loss of the typical shear thinning property of blood. Furthermore, we explored CPDA-1, the gold standard in preserving red blood cells (RBCs), for storage of forensic samples. We found it to be a superior choice for anticoagulation, as the rise of high shear viscosity was attenuated compared to EDTA. When performing oscillation measurements, we found a sudden change of viscoelasticity of blood after 22 days, providing a cut-off for storage time. To highlight the importance of hematological and hemorheological changes upon cold storage, we performed simple drip pattern experiments. These tests revealed a tendency to smaller stain diameters and higher numbers of satellite spatter. While this contradicts expectations from elevated viscosity values, we associate this trend to microscopic inhomogeneities due to storage. We recommend CPDA-1 for prolonged storage of BPA samples and suggest the use of comprehensive test protocols including viscoelasticity for determination of the maximum shelf life of pig blood.

Biochemical indexes of blood of different genotypes of pigs

Changes in technological processes, feeding conditions, content have a great influence on the mechanism of adaptive response of pigs. Distinguish between short-term and long-term adaptation. Long-term adaptation is defined over several generations by reproductive and fattening qualities. Short-term one is studied by blood indexes (biochemical, hematological), ethology, physiological features. There are many stressors that affect pigs, impair their reproductive capacity, digestive processes, and can lead to the death of animals. Therefore, the question now is to create animals of such genotypes, which must have high meat quality and stable homeostasis. With severe stress or constant irritation, this affects the stability of the blood composition. Blood indexes are known to reflect the internal physiological state of animals. Blood reflects hormonal and enzymatic reactions, performs protective functions of the body. That is why we have set the goal of studying the biochemical and hematological indexes of blood of pigs of different genotypes. The study was carried out at the State Enterprise "Stepne" and the laboratories of the Institute of Pig Breeding and agro-industrial production of NAAS. For the study we formed three groups of pigs of 5 heads: purebred the Large White (LW×LW) and local the Large White×Mirgorod (LW×M), the Large White×Mirgorod+1/ 8Pietren(LW×M+1/8P). Blood was taken from pigs in the morning before feeding with a large ear vein. The studies were performed according to conventional methods. Pigs of the LW×M+1/8P local group were found to have high glucose content, an indicator of the effects of stress on the body. Also in this group of pigs were identified leukocytosis, which can be the result of stress. The eosonophils and basophils were slightly underestimated in pigs of the LW×M+1/8P group, which also confirms the previous findings on the reduced stress resistance of pigs. Other indicators that are responsible for the clinical stability of the organism were within normal limits. There was also a slight increase in total protein in pigs in the local LW×M, LW×M+1/8P pigs, which indicates accelerated metabolic processes in the body that can be caused by overfeeding. In purebred LW×LW and local LW×M groups of pigs, all biochemical and hematological parameters of blood were within the normal range, which indicates their stress resistance. Key words: pigs, resistance, adaptation, blood, hematological parameters, biochemical indexes.

Whole-Genome Methylation Analysis Reveals Epigenetic Variation in Cloned and Donor Pigs.

Somatic cloning has had a significant impact on the life sciences and is important in a variety of processes, including medical research and animal production. However, the application of somatic cloning has been limited due to its low success rate. Therefore, potential epigenetic variations between cloned and donor animals are still unclear. DNA methylation, one of the factors which is responsible for phenotypic differences in animals, is a commonly researched topic in epigenetic studies of mammals. To investigate the epigenetic variations between cloned and donor animals, we selected blood and ear fibroblasts of a donor pig and a cloned pig to perform whole-genome bisulfite sequencing (WGBS). A total of 215 and 707 differential methylation genes (DMGs) were identified in blood and ear fibroblasts, respectively. Functional annotation revealed that DMGs are enriched in many pathways, including T/B or natural killer (NK) cell differentiation, oocyte maturation, embryonic development, and reproductive hormone secretion. Moreover, 22 DMGs in the blood and 75 in the ear were associated with immune responses (e.g., CD244, CDK6, CD5, CD2, CD83, and CDC7). We also found that 18 DMGs in blood and 53 in ear fibroblasts were involved in reproduction. Understanding the expression patterns of DMGs, especially in relation to immune responses and reproduction, will reveal insights that will aid the advancement of future somatic cloning techniques in swine.

Ferroportin inhibition attenuates plasma iron, oxidant stress, and renal injury following red blood cell transfusion in guinea pigs.

Red blood cell (RBC) transfusions result in the sequestration and metabolism of storage-damaged RBCs within the spleen and liver. These events are followed by increased plasma iron concentrations that can contribute to oxidant stress and cellular injury. We hypothesized that administration of a ferroportin inhibitor (FPN-INH) immediately after acute RBC exchange transfusion could attenuate posttransfusion circulatory compartment iron exposure, by retaining iron in spleen and hepatic macrophages. Donor guinea pig blood was leukoreduced, and RBCs were preserved at 4°C. Recipient guinea pigs (n = 5/group) were exchange transfused with donor RBCs after refrigerator preservation and dosed intravenously with a small-molecule FPN-INH. Groups included transfusion with vehicle (saline), 5 mg/kg or 25 mg/kg FPN-INH. A time course of RBC morphology, plasma non-transferrin-bound iron (NTBI) and plasma hemoglobin (Hb) were evaluated. End-study spleen, liver, and kidney organ iron levels, as well as renal tissue oxidation and injury, were measured acutely (24-hr after transfusion). RBC transfusion increased plasma NTBI, with maximal concentrations occurring 8 hours after transfusion. Posttransfusion iron accumulation resulted in tubule oxidation and acute kidney injury. FPN inhibition increased spleen and liver parenchymal/macrophage iron accumulation, but attenuated plasma NTBI, and subsequent renal tissue oxidation/injury. In situations of acute RBC transfusion, minimizing circulatory NTBI exposure by FPN inhibition may attenuate organ-specific adverse consequences of iron exposure.

Characteristics of quetiapine and 7-hydroxyquetiapine in hair roots and blood after a single dose of quetiapine

This study investigated the kinetics of quetiapine and its metabolite 7-hydroxyquetiapine in guinea pig blood and hair roots during the whole time course of absorption and elimination after intragastric administration of three dosages (25 mg/kg, 50 mg/kg, 100 mg/kg). The mean maximum concentration (Cmax) values of quetiapine in the blood of the low-, medium- and high-dose groups were 334.4, 849.0, and 2751.1 ng/mL, respectively, and those of 7-hydroxyquetiapine were 75.6, 175.5, and 173.7 ng/mL, respectively. The corresponding mean Cmax values of quetiapine in hair roots were 2.0, 5.9, and 14.7 ng/mg, and those of 7-hydroxyquetiapine were 1.0, 1.8, and 6.4 ng/mg. The mean half-lives of quetiapine at the three dosages in blood were 3.8 h, 5.0 h, and 6.0 h, and those in hair roots were 48.2 h, 41.5 h, and 162.3 h; for 7-hydroxyquetiapine, the values were 2.9 h, 4.1 h, and 4.2 h in blood and 77.1 h, 103.6 h, and 385.9 h in hair roots. The levels of quetiapine in blood and hair roots were higher than those of 7-hydroxyquetiapine, and there were significant positive correlations (p<0.05) between the concentrations of quetiapine and 7-hydroxyquetiapine in hair roots and the respective doses within 24 h and 48 h. Quetiapine and 7-hydroxyquetiapine could still be detected in some guinea pigs even after 28 days, which means that drugs remain in the hair roots longer than in the blood. This finding shows that hair roots could be a good alternative or supplemental matrix to common biological samples such as blood and urine, as hair roots substantially extend the detection window from days to months. Moreover, quetiapine and 7-hydroxyquetiapine were detected within 15min after administration in hair roots, which also suggests that the drug enters the hair roots quickly. Therefore, hair root analysis may be a good choice to detect acute poisoning and single-dose administration if other matrices are unavailable or to provide complementary information for other matrices.

Fluid resuscitation-related coagulation impairment in a porcine hemorrhagic shock model.

BackgroundFast and effective treatment of hemorrhagic shock is one of the most important preclinical trauma care tasks e.g., in combat casualties in avoiding severe end-organ damage or death. In scenarios without immediate availability of blood products, alternate regimens of fluid resuscitation represent the only possibility of maintaining sufficient circulation and regaining adequate end-organ oxygen supply. However, the fluid choice alone may affect the extent of the bleeding by interfering with coagulation pathways. This study investigates the impact of hydroxyethyl starch (HES), gelatine-polysuccinate (GP) and balanced electrolyte solution (BES) as commonly used agents for fluid resuscitation on coagulation using a porcine hemorrhagic shock model.MethodsFollowing approval by the State and Institutional Animal Care Committee, life-threatening hemorrhagic shock was induced via arterial blood withdrawal in 24 anesthetized pigs. Isovolumetric fluid resuscitation with either HES, GP or BES (n = 3 × 8) was performed to compensate for the blood loss. Over four hours, hemodynamics, laboratory parameters and rotational thromboelastometry-derived coagulation were analyzed. As secondary endpoint the porcine values were compared to human blood.ResultsAll the agents used for fluid resuscitation significantly affected coagulation. We measured a restriction of laboratory parameters, clot development and clot firmness, particularly in HES- and GP-treated animals. Hemoglobin content dropped in all groups but showed a more pronounced decline in colloid-treated pigs. This effect was not maintained over the four-hour monitoring period.ConclusionHES, GP, and BEL sufficiently stabilized the macrocirculation, but significantly affected coagulation. These effects were most pronounced after colloid and particularly HES administration. Despite suitability for rapid hemodynamic stabilization, colloids have to be chosen with caution, because their molecular properties may affect coagulation directly and as a consequence of pronounced hemodilution. Our comparison of porcine and human coagulation showed increased coagulation activity in pig blood.

Hepatitis E Virus in Pigs from Slaughterhouses, United States, 2017-2019.

Hepatitis E virus (HEV) RNA was detected in 6.3% and HEV IgG in 40% of 5,033 serum samples from market-weight pigs at 25 slaughterhouses in 10 US states. The prevalent HEV genotype was zoonotic genotype 3, group 2. Blood of HEV-viremic pigs from slaughterhouses may contaminate pork supply chains.

Analysis of microRNA expression profiles in porcine PBMCs after LPS stimulation.

In the present study, we used microRNA (miRNA) sequencing to discover and explore the expression profiles of known and novel miRNAs in 1000 ng/ml LPS stimulated for 8 h vis-à-vis non-stimulated (i.e. control) PBMCs isolated from the blood of healthy pigs. A total of 291 known miRNAs were bio-computationally identified in porcine PBMCs, and 228 novel miRNAs (not enlisted in the swine mirBase) were identified. Among these miRNAs, ssc-miR-148a-3p, ssc-let-7g, ssc-let-7f, 3_8760, ssc-miR-26a, ssc-miR-451, ssc-miR-21, ssc-miR-30d, ssc-miR-99a and ssc-miR-103 were the top 10 most abundant miRNAs in porcine PBMCs. Through miRNA differential analysis combined with quantitative PCR, we found the expressions of ssc-miR-122, ssc-miR-129b, ssc-miR-17-5p and ssc-miR-152 were significantly changed in porcine PBMCs after LPS stimulation. Furthermore, targets prediction and function analysis indicated a significant enrichment in gene ontology functional categories related to diseases, immunity and inflammation. In conclusion, this study on profiling of miRNAs expressed in LPS-stimulated PBMCs provides an important reference point for future studies on regulatory roles of miRNAs in porcine immune system.

Study on the culture of Escherichia coli with different hydrolysis depth of globin

Objective: To explore the effect of culture medium made of peptide fragments of different sizes of globin hydrolyzed by protease on the culture of Escherichia coli. Method: with fresh pig blood as raw material, hydrolyze pig blood protein under fixed conditions, and screen out the enzyme with the highest degree of hydrolysis. Then conduct orthogonal test on the enzyme to determine the best hydrolysis conditions; the beads were obtained under the best hydrolysis conditions. The Escherichia coli was cultured on different peptone culture bases that were prepared by hydrolysate going through different pore size ultrafiltration membrane samples. The culture of Escherichia coli at different hydrolysis depths is determined by detecting the total amount with Escherichia coli detection method. Results: Trypsin has the best hydrolysis effect. The best hydrolysis conditions are as follows: enzyme dosage of 0.2%, hydrolysis time of 12h, temperature of 50°C, initial pH of 7.5 and mass fraction of substrate protein of 8%. Through growth curves of Escherichia coli, it is known that the smaller the pore size of the ultrafiltration membrane, the smaller the molecular weight of the peptide fragment, and the greater the density of the Escherichia coli bacterial solution. Conclusion: Through analyzing the production curves of Escherichia coli in different culture medium, it is concluded that the smaller the molecular weight of the protein peptides, the higher the density of Escherichia coli solution in the LB liquid medium prepared by it, and the better the Escherichia coli culture effect.

Diagnostics of the manifestation of biological laws in animals

Rearing young farm animals in the early stages of postnatal ontogeny is a critical point. There are many aspects of theoretical and practical research on improving the safety and prevention of diseases of calves, but one of the main ones is a comprehensive knowledge of the morphofunctional and adaptive features of calves during the newborn period. To continue to exist in a modified environment is to maintain vital activity and some aspects of homeostasis that are characteristic of organisms of this species, this level of development of its nervous and hormonal mechanisms. When analyzing the incidence and death of calves, it was found that the transfer of calves from individual cells to General ones and the change of milk feeding to hay and mixed feed provokes the growth of diseases at the age of 10 days and older than one month (70%), and also dies at this age (58%). Morpho-physiological features of newborns are the impenetrability of the placenta of hoofed productive animals to the immunoglobulins of the mothers ’ blood. Nature has created a unique mechanism for receiving immunoglobulins in the body of newborn ungulates. After direct maternal immune protection during pregnancy ceases, nature replaces it with colostrum immune protection. To confirm and derive biological laws, the dynamics of immunoglobulins in the blood and colostrum of cows and pigs before and after childbirth were studied.

Характеристика ряда биохимических и антиоксидантных параметров крови хряков породы дюрок, выращиваемых на автоматических кормовых станциях

The aim of the work was to study the biochemical and antioxidant blood parameters of pigs of the Duroc breed. The fattening of pigs was of the same type in terms of the ration and was carried out at automatic feeding stations in OOO «Selective-hybrid center», Voronezh region, Verkhnyaya Khava settlement. The animals were divided into 2 groups depending on the duration of feeding (65 and 72 days as groups 1 and 2, respectively). It was shown that all biochemical and antioxidant parameters of the blood of pigs (of both groups) were within the physiological norms for these animals. However, these indicators slightly differed in a number of values: creatinine – 112,88 and 97,08 mM/L; glucose – 5,33 and 3,88 mM/L; «de Ritis» coefficient – 1,20 and 0,81; alkaline phosphatase – 187,9 and 172,2 IU/L; calcium – 2,74 and 2,48 mM/L; phosphorus – 2,96 and 3,48 mM/L; magnesium – 1,28 and 1,15 mM/L; the total amount of water-soluble antioxidants is 9,77 and 7,50 mg/L for groups 1 and 2, respectively. The interconnection of biochemical and antioxidant parameters of pigs of the Duroc breed (after 65 and 72 days of feeding) was carried out for the first time. These data can be useful for understanding the features of physiological status of pigs and further applications.

Изменение суммарного количества водорастворимых антиоксидантов в сыворотке крови хряков дюрок в зависимости от длительности их откорма

The influence of fattening conditions on the digestive and metabolic processes in animals is actively studied to increase the production of animal food. The aim of the study was to estimate the total amount of water-soluble antioxidants in the blood serum of Duroc boars depending on the duration of fattening. Experiments were conducted on 102 animals to confirm the results of laboratory studies, as well as determination of the total antioxidant activity of pig blood serum by amperometric method. For the first time, a significant difference in antioxidant activity was found in blood samples of Duroc boars with the duration of their fattening from 81 to 101 days.

Physiological response of hemostasis of piglets to excessive thermal effects

Currently, the pig feels the need to further clarify aspects of the physiology of pigs. It is very important to clarify the changes of functional parameters of piglets at the impact of any environmental factors. Negative environmental impact can often particularly adversely affect hemostasis. However, changes its parameters clarified weakly. Objective: to assess changes in hemostasis in piglets undergoing overheating. The research involved 42 pigs at the age of 2.5 months breed: large white, which has experienced overheating during 3 hours as a result of breakdown of air conditioning system. The control group included 32 healthy animals kept in normal conditions of a pigsty. The experienced piglets determined significant increase of platelet aggregation that occur spontaneously and in response to stimulation. Experienced pigs blood coagulation was found high and significant weakening of fibrinolysis. Apparently, the overheating affects animals’ haemorheology and significantly inhibits anabolism. It is clear that in piglets, which suffered from overheating, activated hemostatic system, which affects the microcirculation and inhibits growth. For this reason, there is a great need in the search approaches for leveling in piglets undergoing an episode of overheating, excessive activity of blood coagulation and increased platelet aggregation.

Prenatal inflammation suppresses blood Th1 polarization and gene clusters related to cellular energy metabolism in preterm newborns.

Chorioamnionitis (CA, fetal membrane inflammation) predisposes to preterm birth and is associated with increased neonatal infection risk, but the separate effects of prematurity, CA, and postnatal adaptations on this risk are unclear. Using pigs as models for infants, we examined the systemic immune-metabolic status in cesarean-delivered preterm pigs, with and without CA induced by intra-amniotic (IA) LPS exposure. At birth, cord blood of preterm pigs showed neutropenia and low expressions of innate and adaptive immune genes, relative to term pigs. IA LPS induced CA and fetal systemic innate immune activation via complement and neutrophil-related pathways. These were mainly modulated via cellular regulations rather than granulopoiesis, as validated by the in vitro LPS stimulation of cord blood. After birth, IA LPS-exposed preterm pigs did not follow normal immune-metabolic ontogenies found in fetuses or newborns without prenatal insults, but showed consistently high levels of Treg, impaired Th1 polarization, and reduced expressions of multiple genes related to cellular oxidative phosphorylation and ribosomal activities. In conclusion, our results provide cellular and molecular evidence for CA-induced distinct neonatal immune-metabolic status with increased disease tolerance strategy, suggesting mechanisms for the clinical observation of elevated sepsis risks in immune-compromised preterm infants born with CA.

The level of endogenic intoxication in the dynamics of development of experimental contact dermatitis and experimental pneumonia and their correction by thiotriazoline

Тhe aim of our work was to find out the peculiarities of changes ofendogenous intoxication indices in guinea pig blood during theformation of combined pathology - experimental contact dermatitis and experimental pneumonia and correction of their disorders with thiotriazoline.The paper found a gradual increase in the molecules of mediummass and erythrocyte index of intoxication in guinea pig serum with experimental contact dermatitis and experimental pneumonia with the highest degree of expression on the 18thday of the experiment, and this may be may indicate the development of endogenous intoxication of the animal body. At the same time, the use of the drug thiotriazoline caused the decrease of the studied indicators, which gives grounds to stateits positive effect on certain markers of endogenous intoxicationand the feasibility of further research.

Evidence for the presence of African swine fever virus in apparently healthy pigs in South-Kivu Province of the Democratic Republic of Congo

African swine fever (ASF) is the most important disease constraining smallholder pig production in the Democratic Republic of Congo, causing high mortality in domestic pigs with severe impacts on the livelihoods of local populations. This study was conducted with the aim of determining the prevalence of ASF and circulating virus genotypes in asymptomatic pigs raised on smallholder farms in the South Kivu province to understand the transmission dynamics of ASF and ultimately improving disease control. A cross-sectional survey was carried out in 5 districts where 267 pig blood were screened for both antibody and viral genome using indirect Enzyme Linked Immunosorbent Assay (ELISA) and polymerase chain reaction (PCR) respectively. Additionally, amplicons from PCR positive samples were sequenced by Sanger method for genetic analysis of ASF virus (ASFV) based on the C-terminal region of the B646L gene that encodes the major capsid protein p72 and the gene E183L encoding the p54 protein. The overall seroprevalence obtained based on antibody to p30 protein was 37 % and was significantly higher (P < 0.05) in adult (>1 year) animals (44.7 %) than in younger (<1 year) ones (33.5 %). Moreover, the seropositivity varied significantly (P < 0.05) according to the pig husbandry system practiced within the districts investigated with Uvira (55 %) and Mwenga (42.2 %) having the highest ASFV antibodies, while the lowest (10.5 %) were in Kalehe. Free-range pigs exhibited a higher level of seropositivity to ASFV antibody (68.9 %) than pigs kept in the pigsty housing system (21.6 %). However, no statistically significant differences (P > 0.05) were observed when sex of the animal and breed were factored. PCR detection of ASFV amplified a specific band of expected size (257 bp) in 61 out of 267 blood samples, confirming the presence of the viral DNA in 22.8 % of asymptomatic domestic pigs. Statistical analysis revealed that ASFV infection in domestic pigs varied significantly (p < 0.001) according to geographical location and breed, with the highest infection rate found in Walungu district (33.7 %) while the lowest was registered in Kalehe (15.8 %). Local pigs (27.2 %) were more infected than crosses (9.2 %).Phylogenetic analyses based on partial sequences of the p72 and p54 genes revealed that all the ASFV detected belonged to genotype IX, which has previously been reported in other parts of DR Congo, and was clustered together with isolates from Kenya, Uganda and Republic of Congo. This study avails the first evidence of the presence of ASF virus in domestic pigs in the absence of outbreaks in South Kivu province, eastern DR Congo, indicating a need to raise awareness among pig farmers and veterinary authorities on the application of biosecurity measures and good husbandry practices to control the disease.